Leeds Method: Consolidating Clusters, An Example

I posted earlier this week about how and why you might need to consolidate (or combine) your color clusters on your Leeds Method chart. Today, I’d like to share an example from a reader named Bruce.

Original 9 Clusters

When Bruce sent me his chart, he had sorted 50 people into 9 clusters:

With a lot of clusters and a lot of overlap, Bruce’s chart would be more helpful if we consolidated some of his clusters. Although not always possible, we are hoping to be able to create 4 clusters based on his 4 grandparent lines.

Rearranging the Clusters

To consolidate clusters, I first rearrange them by putting clusters with overlap next to each other as seen below:

In Bruce’s case, we have overlap with the following clusters:

• • Clusters C, D, & E
  • Clusters F, G, & H
  • Clusters I & J

Next we look to see if there is “heavy overlap.” In other words, do most of the people in one color cluster also belong to another color cluster? Let’s look at two examples:

• • Do most of the people in Cluster D (gold) also belong in Cluster C (bright red)? Yes, they do. So I would consolidate or combine these two clusters into Cluster C. We would then ask the same question about Cluster E: Do most of the people in Cluster E (red) also belong in Cluster C (bright red)? Yes, they do. So I would consolidate or combine these two clusters into Cluster C. That means that Clusters C, D, & E were combined into one Cluster: the Red Cluster (C).
  • Do most of the people in Cluster J (light blue) also belong in Cluster I (dark blue)? Yes, they do. So I would consolidate or combine these two clusters into Cluster I.

Consolidating Clusters

In this case, I consolidated as follows:

• • clusters C, D, & E into a Red Cluster
  • clusters F, G, & H into a Green Cluster
  • clusters I & J into a Blue Cluster
  • (Note that the Yellow Cluster, with just a single person, was left alone)

We get the following chart:

Now Bruce has 4 clusters, which is a “best case” scenario! These 4 clusters likely represent his 4 grandparent lines.

Bruce has been able to identify the Red and Green Clusters as belonging to his maternal grandfather and grandmother. He has a mystery on his dad’s side, so hopefully he will find the answer by researching the Blue and Yellow Clusters!

Adding Higher Matches

Let’s take this a step further and talk about the next step. The next step would be to add any higher matches. If some of these higher matches are related to you through 2 grandparent lines, they will likely match 2 Color Clusters.

In Bruce’s case, he only has 1 match above 400. This match only shares 401 cM. Interestingly, the person matches both the Blue and Yellow Clusters supporting the idea that the Blue and Yellow Clusters are paternal while the Red and Green Clusters are maternal. If Bruce can figure out this person’s 4 grandparents, it might help him with his own mystery!

Any Questions?

I hope this helped as you figure out how to consolidate your own clusters. If you have any questions, please feel free to ask!